An ancient civilization is defined to be in the Bronze Age either by producing bronze by smelting its own copper and alloying with tin, arsenic, or other metals, or by trading for bronze from production areas elsewhere. Bronze itself is harder and more durable than other metals available at the time, allowing Bronze Age civilizations to gain a technological advantage.

Copper-tin ores are rare, as reflected in the fact that there were no tin bronzes in Western Asia before trading in bronze began in the 3rd millennium BC. Worldwide, the Bronze Age generally followed the Neolithic period, with the Chalcolithic serving as a transition. Although the Iron Age generally followed the Bronze Age, in some areas (such as Sub-Saharan Africa), the Iron Age intruded directly on the Neolithic.